# Pure python AES128 implementation
# SciresM, 2017
from struct import unpack as up, pack as pk
from binascii import hexlify as hx, unhexlify as uhx
from Crypto.Cipher import AES
from Crypto.Util import Counter

def sxor(s1, s2):
	assert(len(s1) == len(s2))
	return b''.join([pk('B', x ^ y) for x, y in zip(s1, s2)])

class AESCBC:
	'''Class for performing AES CBC cipher operations.'''

	def __init__(self, key, iv):
		self.aes = AESECB(key)
		if len(iv) != self.aes.block_size:
			raise ValueError('IV must be of size %X!' % self.aes.block_size)
		self.iv = iv

	def encrypt(self, data, iv=None):
		'''Encrypts some data in CBC mode.'''
		if iv is None:
			iv = self.iv
		out = b''
		while data:
			encb = self.aes.encrypt_block_ecb(sxor(data[:0x10], iv))
			out += encb
			iv = encb
			data = data[0x10:]
		return out

	def decrypt(self, data, iv=None):
		'''Decrypts some data in CBC mode.'''
		if len(data) % self.aes.block_size:
			raise ValueError('Data is not aligned to block size!')
		if iv is None:
			iv = self.iv
		out = b''
		while data:
			decb = sxor(self.aes.decrypt_block_ecb(data[:0x10]), iv)
			out += decb
			iv = data[:0x10]
			data = data[0x10:]
		return out

	def set_iv(self, iv):
		if len(iv) != self.aes.block_size:
			raise ValueError('IV must be of size %X!' % self.aes.block_size)
		self.iv = iv

class AESCTR:
	'''Class for performing AES CTR cipher operations.'''

	def __init__(self, key, nonce, offset=0):
		self.key = key
		self.nonce = nonce
		self.seek(offset)

	def encrypt(self, data, ctr=None):
		if ctr is None:
			ctr = self.ctr
		return self.aes.encrypt(data)

	def decrypt(self, data, ctr=None):
		return self.encrypt(data, ctr)

	def seek(self, offset):
		self.ctr = Counter.new(64, prefix=self.nonce[0:8], initial_value=(offset >> 4))
		self.aes = AES.new(self.key, AES.MODE_CTR, counter=self.ctr)

	def bktrPrefix(self, ctr_val):
		return self.nonce[0:4] + ctr_val.to_bytes(4, 'big')

	def bktrSeek(self, offset, ctr_val, virtualOffset=0):
		offset += virtualOffset
		self.ctr = Counter.new(64, prefix=self.bktrPrefix(ctr_val), initial_value=(offset >> 4))
		self.aes = AES.new(self.key, AES.MODE_CTR, counter=self.ctr)

class AESXTS:
	'''Class for performing AES XTS cipher operations'''

	def __init__(self, keys, sector=0):
		self.keys = keys[:16], keys[16:]
		if not(isinstance(self.keys, tuple) and len(self.keys) == 2):
			raise TypeError('XTS mode requires a tuple of two keys.')
		self.K1 = AESECB(self.keys[0])
		self.K2 = AESECB(self.keys[1])

		self.sector = sector
		self.block_size = self.K1.block_size

		self.sector_size = 0x200

	def encrypt(self, data, sector=None):
		if sector is None:
			sector = self.sector
		if len(data) % self.block_size:
			raise ValueError('Data is not aligned to block size!')
		out = b''
		while data:
			tweak = self.get_tweak(sector)
			out += self.encrypt_sector(data[:self.sector_size], tweak)
			data = data[self.sector_size:]
			sector += 1
		return out

	def encrypt_sector(self, data, tweak):
		if len(data) % self.block_size:
			raise ValueError('Data is not aligned to block size!')
		out = b''
		tweak = self.K2.encrypt(uhx('%032X' % tweak))
		while data:
			out += sxor(tweak, self.K1.encrypt(sxor(data[:0x10], tweak)))
			_t = int(hx(tweak[::-1]), 16)
			_t <<= 1
			if _t & (1 << 128):
				_t ^= ((1 << 128) | (0x87))
			tweak = uhx('%032X' % _t)[::-1]
			data = data[0x10:]
		return out

	def decrypt(self, data, sector=None):
		if sector is None:
			sector = self.sector
		if len(data) % self.block_size:
			raise ValueError('Data is not aligned to block size!')
		out = b''
		while data:
			tweak = self.get_tweak(sector)
			out += self.decrypt_sector(data[:self.sector_size], tweak)
			data = data[self.sector_size:]
			sector += 1
		return out

	def decrypt_sector(self, data, tweak):
		if len(data) % self.block_size:
			raise ValueError('Data is not aligned to block size!')
		out = b''
		tweak = self.K2.encrypt(uhx('%032X' % tweak))
		while data:
			a = self.K1.decrypt(sxor(data[:0x10], tweak))
			out += sxor(tweak, a)
			_t = int(hx(tweak[::-1]), 16)
			_t <<= 1
			if _t & (1 << 128):
				_t ^= ((1 << 128) | (0x87))
			tweak = uhx('%032X' % _t)[::-1]
			data = data[0x10:]
		return out

	def get_tweak(self, sector=None):
		if sector is None:
			sector = self.sector
		tweak = 0
		for i in range(self.block_size):
			tweak |= (sector & 0xFF) << (i * 8)
			sector >>= 8
		return tweak

	def set_sector(self, sector):
		self.sector = sector

class AESXTSN:
	'''Class for performing Nintendo AES XTS cipher operations'''

	def __init__(self, keys, sector_size=0x200, sector=0):
		if not(isinstance(keys, tuple) and len(keys) == 2):
			raise TypeError('XTS mode requires a tuple of two keys.')
		self.K1 = AESECB(keys[0])
		self.K2 = AESECB(keys[1])
		self.keys = keys
		self.sector = sector
		self.sector_size = sector_size
		self.block_size = self.K1.block_size

	def encrypt(self, data, sector=None):
		if sector is None:
			sector = self.sector
		if len(data) % self.block_size:
			raise ValueError('Data is not aligned to block size!')
		out = b''
		while data:
			tweak = self.get_tweak(sector)
			out += self.encrypt_sector(data[:self.sector_size], tweak)
			data = data[self.sector_size:]
			sector += 1
		return out

	def encrypt_sector(self, data, tweak):
		if len(data) % self.block_size:
			raise ValueError('Data is not aligned to block size!')
		out = b''
		tweak = self.K2.encrypt(uhx('%032X' % tweak))
		while data:
			out += sxor(tweak, self.K1.encrypt_block_ecb(sxor(data[:0x10], tweak)))
			_t = int(hx(tweak[::-1]), 16)
			_t <<= 1
			if _t & (1 << 128):
				_t ^= ((1 << 128) | (0x87))
			tweak = uhx('%032X' % _t)[::-1]
			data = data[0x10:]
		return out

	def decrypt(self, data, sector=None):
		if sector is None:
			sector = self.sector
		if len(data) % self.block_size:
			raise ValueError('Data is not aligned to block size!')
		out = b''
		while data:
			tweak = self.get_tweak(sector)
			out += self.decrypt_sector(data[:self.sector_size], tweak)
			data = data[self.sector_size:]
			sector += 1
		return out

	def decrypt_sector(self, data, tweak):
		if len(data) % self.block_size:
			raise ValueError('Data is not aligned to block size!')
		out = b''
		tweak = self.K2.encrypt(uhx('%032X' % tweak))
		while data:
			out += sxor(tweak, self.K1.decrypt_block_ecb(sxor(data[:0x10], tweak)))
			_t = int(hx(tweak[::-1]), 16)
			_t <<= 1
			if _t & (1 << 128):
				_t ^= ((1 << 128) | (0x87))
			tweak = uhx('%032X' % _t)[::-1]
			data = data[0x10:]
		return out

	def get_tweak(self, sector=None):
		'''Gets tweak for use in XEX.'''
		if sector is None:
			sector = self.sector
		tweak = 0
		for i in range(self.block_size):
			tweak |= (sector & 0xFF) << (i * 8)
			sector >>= 8
		return tweak

	def set_sector(self, sector):
		self.sector = sector

	def set_sector_size(self, sector_size):
		self.sector_size = sector_size

class AESECB:
	'''Class for performing AES ECB cipher operations.'''

	# Constants for performing AES operations -- rcon table, S boxes.
	rcon_table = [
		0x8d,
		0x01,
		0x02,
		0x04,
		0x08,
		0x10,
		0x20,
		0x40,
		0x80,
		0x1b,
		0x36,
		0x6c,
		0xd8,
		0xab,
		0x4d,
		0x9a,
		0x2f,
		0x5e,
		0xbc,
		0x63,
		0xc6,
		0x97,
		0x35,
		0x6a,
		0xd4,
		0xb3,
		0x7d,
		0xfa,
		0xef,
		0xc5,
		0x91,
		0x39,
		0x72,
		0xe4,
		0xd3,
		0xbd,
		0x61,
		0xc2,
		0x9f,
		0x25,
		0x4a,
		0x94,
		0x33,
		0x66,
		0xcc,
		0x83,
		0x1d,
		0x3a,
		0x74,
		0xe8,
		0xcb,
		0x8d,
		0x01,
		0x02,
		0x04,
		0x08,
		0x10,
		0x20,
		0x40,
		0x80,
		0x1b,
		0x36,
		0x6c,
		0xd8,
		0xab,
		0x4d,
		0x9a,
		0x2f,
		0x5e,
		0xbc,
		0x63,
		0xc6,
		0x97,
		0x35,
		0x6a,
		0xd4,
		0xb3,
		0x7d,
		0xfa,
		0xef,
		0xc5,
		0x91,
		0x39,
		0x72,
		0xe4,
		0xd3,
		0xbd,
		0x61,
		0xc2,
		0x9f,
		0x25,
		0x4a,
		0x94,
		0x33,
		0x66,
		0xcc,
		0x83,
		0x1d,
		0x3a,
		0x74,
		0xe8,
		0xcb,
		0x8d,
		0x01,
		0x02,
		0x04,
		0x08,
		0x10,
		0x20,
		0x40,
		0x80,
		0x1b,
		0x36,
		0x6c,
		0xd8,
		0xab,
		0x4d,
		0x9a,
		0x2f,
		0x5e,
		0xbc,
		0x63,
		0xc6,
		0x97,
		0x35,
		0x6a,
		0xd4,
		0xb3,
		0x7d,
		0xfa,
		0xef,
		0xc5,
		0x91,
		0x39,
		0x72,
		0xe4,
		0xd3,
		0xbd,
		0x61,
		0xc2,
		0x9f,
		0x25,
		0x4a,
		0x94,
		0x33,
		0x66,
		0xcc,
		0x83,
		0x1d,
		0x3a,
		0x74,
		0xe8,
		0xcb,
		0x8d,
		0x01,
		0x02,
		0x04,
		0x08,
		0x10,
		0x20,
		0x40,
		0x80,
		0x1b,
		0x36,
		0x6c,
		0xd8,
		0xab,
		0x4d,
		0x9a,
		0x2f,
		0x5e,
		0xbc,
		0x63,
		0xc6,
		0x97,
		0x35,
		0x6a,
		0xd4,
		0xb3,
		0x7d,
		0xfa,
		0xef,
		0xc5,
		0x91,
		0x39,
		0x72,
		0xe4,
		0xd3,
		0xbd,
		0x61,
		0xc2,
		0x9f,
		0x25,
		0x4a,
		0x94,
		0x33,
		0x66,
		0xcc,
		0x83,
		0x1d,
		0x3a,
		0x74,
		0xe8,
		0xcb,
		0x8d,
		0x01,
		0x02,
		0x04,
		0x08,
		0x10,
		0x20,
		0x40,
		0x80,
		0x1b,
		0x36,
		0x6c,
		0xd8,
		0xab,
		0x4d,
		0x9a,
		0x2f,
		0x5e,
		0xbc,
		0x63,
		0xc6,
		0x97,
		0x35,
		0x6a,
		0xd4,
		0xb3,
		0x7d,
		0xfa,
		0xef,
		0xc5,
		0x91,
		0x39,
		0x72,
		0xe4,
		0xd3,
		0xbd,
		0x61,
		0xc2,
		0x9f,
		0x25,
		0x4a,
		0x94,
		0x33,
		0x66,
		0xcc,
		0x83,
		0x1d,
		0x3a,
		0x74,
		0xe8,
		0xcb,
		0x8d]
	sbox_enc = [0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76,
				0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0,
				0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15,
				0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75,
				0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84,
				0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf,
				0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8,
				0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2,
				0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73,
				0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb,
				0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79,
				0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08,
				0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a,
				0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e,
				0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf,
				0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16]

	sbox_dec = [0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb,
				0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb,
				0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e,
				0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25,
				0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92,
				0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84,
				0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06,
				0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b,
				0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73,
				0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e,
				0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b,
				0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4,
				0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f,
				0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef,
				0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61,
				0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d]

	mult_1_table = range(0x100)
	mult_2_table = [
		0x00,
		0x02,
		0x04,
		0x06,
		0x08,
		0x0a,
		0x0c,
		0x0e,
		0x10,
		0x12,
		0x14,
		0x16,
		0x18,
		0x1a,
		0x1c,
		0x1e,
		0x20,
		0x22,
		0x24,
		0x26,
		0x28,
		0x2a,
		0x2c,
		0x2e,
		0x30,
		0x32,
		0x34,
		0x36,
		0x38,
		0x3a,
		0x3c,
		0x3e,
		0x40,
		0x42,
		0x44,
		0x46,
		0x48,
		0x4a,
		0x4c,
		0x4e,
		0x50,
		0x52,
		0x54,
		0x56,
		0x58,
		0x5a,
		0x5c,
		0x5e,
		0x60,
		0x62,
		0x64,
		0x66,
		0x68,
		0x6a,
		0x6c,
		0x6e,
		0x70,
		0x72,
		0x74,
		0x76,
		0x78,
		0x7a,
		0x7c,
		0x7e,
		0x80,
		0x82,
		0x84,
		0x86,
		0x88,
		0x8a,
		0x8c,
		0x8e,
		0x90,
		0x92,
		0x94,
		0x96,
		0x98,
		0x9a,
		0x9c,
		0x9e,
		0xa0,
		0xa2,
		0xa4,
		0xa6,
		0xa8,
		0xaa,
		0xac,
		0xae,
		0xb0,
		0xb2,
		0xb4,
		0xb6,
		0xb8,
		0xba,
		0xbc,
		0xbe,
		0xc0,
		0xc2,
		0xc4,
		0xc6,
		0xc8,
		0xca,
		0xcc,
		0xce,
		0xd0,
		0xd2,
		0xd4,
		0xd6,
		0xd8,
		0xda,
		0xdc,
		0xde,
		0xe0,
		0xe2,
		0xe4,
		0xe6,
		0xe8,
		0xea,
		0xec,
		0xee,
		0xf0,
		0xf2,
		0xf4,
		0xf6,
		0xf8,
		0xfa,
		0xfc,
		0xfe,
		0x1b,
		0x19,
		0x1f,
		0x1d,
		0x13,
		0x11,
		0x17,
		0x15,
		0x0b,
		0x09,
		0x0f,
		0x0d,
		0x03,
		0x01,
		0x07,
		0x05,
		0x3b,
		0x39,
		0x3f,
		0x3d,
		0x33,
		0x31,
		0x37,
		0x35,
		0x2b,
		0x29,
		0x2f,
		0x2d,
		0x23,
		0x21,
		0x27,
		0x25,
		0x5b,
		0x59,
		0x5f,
		0x5d,
		0x53,
		0x51,
		0x57,
		0x55,
		0x4b,
		0x49,
		0x4f,
		0x4d,
		0x43,
		0x41,
		0x47,
		0x45,
		0x7b,
		0x79,
		0x7f,
		0x7d,
		0x73,
		0x71,
		0x77,
		0x75,
		0x6b,
		0x69,
		0x6f,
		0x6d,
		0x63,
		0x61,
		0x67,
		0x65,
		0x9b,
		0x99,
		0x9f,
		0x9d,
		0x93,
		0x91,
		0x97,
		0x95,
		0x8b,
		0x89,
		0x8f,
		0x8d,
		0x83,
		0x81,
		0x87,
		0x85,
		0xbb,
		0xb9,
		0xbf,
		0xbd,
		0xb3,
		0xb1,
		0xb7,
		0xb5,
		0xab,
		0xa9,
		0xaf,
		0xad,
		0xa3,
		0xa1,
		0xa7,
		0xa5,
		0xdb,
		0xd9,
		0xdf,
		0xdd,
		0xd3,
		0xd1,
		0xd7,
		0xd5,
		0xcb,
		0xc9,
		0xcf,
		0xcd,
		0xc3,
		0xc1,
		0xc7,
		0xc5,
		0xfb,
		0xf9,
		0xff,
		0xfd,
		0xf3,
		0xf1,
		0xf7,
		0xf5,
		0xeb,
		0xe9,
		0xef,
		0xed,
		0xe3,
		0xe1,
		0xe7,
		0xe5]
	mult_3_table = [
		0x00,
		0x03,
		0x06,
		0x05,
		0x0c,
		0x0f,
		0x0a,
		0x09,
		0x18,
		0x1b,
		0x1e,
		0x1d,
		0x14,
		0x17,
		0x12,
		0x11,
		0x30,
		0x33,
		0x36,
		0x35,
		0x3c,
		0x3f,
		0x3a,
		0x39,
		0x28,
		0x2b,
		0x2e,
		0x2d,
		0x24,
		0x27,
		0x22,
		0x21,
		0x60,
		0x63,
		0x66,
		0x65,
		0x6c,
		0x6f,
		0x6a,
		0x69,
		0x78,
		0x7b,
		0x7e,
		0x7d,
		0x74,
		0x77,
		0x72,
		0x71,
		0x50,
		0x53,
		0x56,
		0x55,
		0x5c,
		0x5f,
		0x5a,
		0x59,
		0x48,
		0x4b,
		0x4e,
		0x4d,
		0x44,
		0x47,
		0x42,
		0x41,
		0xc0,
		0xc3,
		0xc6,
		0xc5,
		0xcc,
		0xcf,
		0xca,
		0xc9,
		0xd8,
		0xdb,
		0xde,
		0xdd,
		0xd4,
		0xd7,
		0xd2,
		0xd1,
		0xf0,
		0xf3,
		0xf6,
		0xf5,
		0xfc,
		0xff,
		0xfa,
		0xf9,
		0xe8,
		0xeb,
		0xee,
		0xed,
		0xe4,
		0xe7,
		0xe2,
		0xe1,
		0xa0,
		0xa3,
		0xa6,
		0xa5,
		0xac,
		0xaf,
		0xaa,
		0xa9,
		0xb8,
		0xbb,
		0xbe,
		0xbd,
		0xb4,
		0xb7,
		0xb2,
		0xb1,
		0x90,
		0x93,
		0x96,
		0x95,
		0x9c,
		0x9f,
		0x9a,
		0x99,
		0x88,
		0x8b,
		0x8e,
		0x8d,
		0x84,
		0x87,
		0x82,
		0x81,
		0x9b,
		0x98,
		0x9d,
		0x9e,
		0x97,
		0x94,
		0x91,
		0x92,
		0x83,
		0x80,
		0x85,
		0x86,
		0x8f,
		0x8c,
		0x89,
		0x8a,
		0xab,
		0xa8,
		0xad,
		0xae,
		0xa7,
		0xa4,
		0xa1,
		0xa2,
		0xb3,
		0xb0,
		0xb5,
		0xb6,
		0xbf,
		0xbc,
		0xb9,
		0xba,
		0xfb,
		0xf8,
		0xfd,
		0xfe,
		0xf7,
		0xf4,
		0xf1,
		0xf2,
		0xe3,
		0xe0,
		0xe5,
		0xe6,
		0xef,
		0xec,
		0xe9,
		0xea,
		0xcb,
		0xc8,
		0xcd,
		0xce,
		0xc7,
		0xc4,
		0xc1,
		0xc2,
		0xd3,
		0xd0,
		0xd5,
		0xd6,
		0xdf,
		0xdc,
		0xd9,
		0xda,
		0x5b,
		0x58,
		0x5d,
		0x5e,
		0x57,
		0x54,
		0x51,
		0x52,
		0x43,
		0x40,
		0x45,
		0x46,
		0x4f,
		0x4c,
		0x49,
		0x4a,
		0x6b,
		0x68,
		0x6d,
		0x6e,
		0x67,
		0x64,
		0x61,
		0x62,
		0x73,
		0x70,
		0x75,
		0x76,
		0x7f,
		0x7c,
		0x79,
		0x7a,
		0x3b,
		0x38,
		0x3d,
		0x3e,
		0x37,
		0x34,
		0x31,
		0x32,
		0x23,
		0x20,
		0x25,
		0x26,
		0x2f,
		0x2c,
		0x29,
		0x2a,
		0x0b,
		0x08,
		0x0d,
		0x0e,
		0x07,
		0x04,
		0x01,
		0x02,
		0x13,
		0x10,
		0x15,
		0x16,
		0x1f,
		0x1c,
		0x19,
		0x1a]

	mult_9_table = [
		0x00,
		0x09,
		0x12,
		0x1b,
		0x24,
		0x2d,
		0x36,
		0x3f,
		0x48,
		0x41,
		0x5a,
		0x53,
		0x6c,
		0x65,
		0x7e,
		0x77,
		0x90,
		0x99,
		0x82,
		0x8b,
		0xb4,
		0xbd,
		0xa6,
		0xaf,
		0xd8,
		0xd1,
		0xca,
		0xc3,
		0xfc,
		0xf5,
		0xee,
		0xe7,
		0x3b,
		0x32,
		0x29,
		0x20,
		0x1f,
		0x16,
		0x0d,
		0x04,
		0x73,
		0x7a,
		0x61,
		0x68,
		0x57,
		0x5e,
		0x45,
		0x4c,
		0xab,
		0xa2,
		0xb9,
		0xb0,
		0x8f,
		0x86,
		0x9d,
		0x94,
		0xe3,
		0xea,
		0xf1,
		0xf8,
		0xc7,
		0xce,
		0xd5,
		0xdc,
		0x76,
		0x7f,
		0x64,
		0x6d,
		0x52,
		0x5b,
		0x40,
		0x49,
		0x3e,
		0x37,
		0x2c,
		0x25,
		0x1a,
		0x13,
		0x08,
		0x01,
		0xe6,
		0xef,
		0xf4,
		0xfd,
		0xc2,
		0xcb,
		0xd0,
		0xd9,
		0xae,
		0xa7,
		0xbc,
		0xb5,
		0x8a,
		0x83,
		0x98,
		0x91,
		0x4d,
		0x44,
		0x5f,
		0x56,
		0x69,
		0x60,
		0x7b,
		0x72,
		0x05,
		0x0c,
		0x17,
		0x1e,
		0x21,
		0x28,
		0x33,
		0x3a,
		0xdd,
		0xd4,
		0xcf,
		0xc6,
		0xf9,
		0xf0,
		0xeb,
		0xe2,
		0x95,
		0x9c,
		0x87,
		0x8e,
		0xb1,
		0xb8,
		0xa3,
		0xaa,
		0xec,
		0xe5,
		0xfe,
		0xf7,
		0xc8,
		0xc1,
		0xda,
		0xd3,
		0xa4,
		0xad,
		0xb6,
		0xbf,
		0x80,
		0x89,
		0x92,
		0x9b,
		0x7c,
		0x75,
		0x6e,
		0x67,
		0x58,
		0x51,
		0x4a,
		0x43,
		0x34,
		0x3d,
		0x26,
		0x2f,
		0x10,
		0x19,
		0x02,
		0x0b,
		0xd7,
		0xde,
		0xc5,
		0xcc,
		0xf3,
		0xfa,
		0xe1,
		0xe8,
		0x9f,
		0x96,
		0x8d,
		0x84,
		0xbb,
		0xb2,
		0xa9,
		0xa0,
		0x47,
		0x4e,
		0x55,
		0x5c,
		0x63,
		0x6a,
		0x71,
		0x78,
		0x0f,
		0x06,
		0x1d,
		0x14,
		0x2b,
		0x22,
		0x39,
		0x30,
		0x9a,
		0x93,
		0x88,
		0x81,
		0xbe,
		0xb7,
		0xac,
		0xa5,
		0xd2,
		0xdb,
		0xc0,
		0xc9,
		0xf6,
		0xff,
		0xe4,
		0xed,
		0x0a,
		0x03,
		0x18,
		0x11,
		0x2e,
		0x27,
		0x3c,
		0x35,
		0x42,
		0x4b,
		0x50,
		0x59,
		0x66,
		0x6f,
		0x74,
		0x7d,
		0xa1,
		0xa8,
		0xb3,
		0xba,
		0x85,
		0x8c,
		0x97,
		0x9e,
		0xe9,
		0xe0,
		0xfb,
		0xf2,
		0xcd,
		0xc4,
		0xdf,
		0xd6,
		0x31,
		0x38,
		0x23,
		0x2a,
		0x15,
		0x1c,
		0x07,
		0x0e,
		0x79,
		0x70,
		0x6b,
		0x62,
		0x5d,
		0x54,
		0x4f,
		0x46]
	mult_B_table = [
		0x00,
		0x0b,
		0x16,
		0x1d,
		0x2c,
		0x27,
		0x3a,
		0x31,
		0x58,
		0x53,
		0x4e,
		0x45,
		0x74,
		0x7f,
		0x62,
		0x69,
		0xb0,
		0xbb,
		0xa6,
		0xad,
		0x9c,
		0x97,
		0x8a,
		0x81,
		0xe8,
		0xe3,
		0xfe,
		0xf5,
		0xc4,
		0xcf,
		0xd2,
		0xd9,
		0x7b,
		0x70,
		0x6d,
		0x66,
		0x57,
		0x5c,
		0x41,
		0x4a,
		0x23,
		0x28,
		0x35,
		0x3e,
		0x0f,
		0x04,
		0x19,
		0x12,
		0xcb,
		0xc0,
		0xdd,
		0xd6,
		0xe7,
		0xec,
		0xf1,
		0xfa,
		0x93,
		0x98,
		0x85,
		0x8e,
		0xbf,
		0xb4,
		0xa9,
		0xa2,
		0xf6,
		0xfd,
		0xe0,
		0xeb,
		0xda,
		0xd1,
		0xcc,
		0xc7,
		0xae,
		0xa5,
		0xb8,
		0xb3,
		0x82,
		0x89,
		0x94,
		0x9f,
		0x46,
		0x4d,
		0x50,
		0x5b,
		0x6a,
		0x61,
		0x7c,
		0x77,
		0x1e,
		0x15,
		0x08,
		0x03,
		0x32,
		0x39,
		0x24,
		0x2f,
		0x8d,
		0x86,
		0x9b,
		0x90,
		0xa1,
		0xaa,
		0xb7,
		0xbc,
		0xd5,
		0xde,
		0xc3,
		0xc8,
		0xf9,
		0xf2,
		0xef,
		0xe4,
		0x3d,
		0x36,
		0x2b,
		0x20,
		0x11,
		0x1a,
		0x07,
		0x0c,
		0x65,
		0x6e,
		0x73,
		0x78,
		0x49,
		0x42,
		0x5f,
		0x54,
		0xf7,
		0xfc,
		0xe1,
		0xea,
		0xdb,
		0xd0,
		0xcd,
		0xc6,
		0xaf,
		0xa4,
		0xb9,
		0xb2,
		0x83,
		0x88,
		0x95,
		0x9e,
		0x47,
		0x4c,
		0x51,
		0x5a,
		0x6b,
		0x60,
		0x7d,
		0x76,
		0x1f,
		0x14,
		0x09,
		0x02,
		0x33,
		0x38,
		0x25,
		0x2e,
		0x8c,
		0x87,
		0x9a,
		0x91,
		0xa0,
		0xab,
		0xb6,
		0xbd,
		0xd4,
		0xdf,
		0xc2,
		0xc9,
		0xf8,
		0xf3,
		0xee,
		0xe5,
		0x3c,
		0x37,
		0x2a,
		0x21,
		0x10,
		0x1b,
		0x06,
		0x0d,
		0x64,
		0x6f,
		0x72,
		0x79,
		0x48,
		0x43,
		0x5e,
		0x55,
		0x01,
		0x0a,
		0x17,
		0x1c,
		0x2d,
		0x26,
		0x3b,
		0x30,
		0x59,
		0x52,
		0x4f,
		0x44,
		0x75,
		0x7e,
		0x63,
		0x68,
		0xb1,
		0xba,
		0xa7,
		0xac,
		0x9d,
		0x96,
		0x8b,
		0x80,
		0xe9,
		0xe2,
		0xff,
		0xf4,
		0xc5,
		0xce,
		0xd3,
		0xd8,
		0x7a,
		0x71,
		0x6c,
		0x67,
		0x56,
		0x5d,
		0x40,
		0x4b,
		0x22,
		0x29,
		0x34,
		0x3f,
		0x0e,
		0x05,
		0x18,
		0x13,
		0xca,
		0xc1,
		0xdc,
		0xd7,
		0xe6,
		0xed,
		0xf0,
		0xfb,
		0x92,
		0x99,
		0x84,
		0x8f,
		0xbe,
		0xb5,
		0xa8,
		0xa3]
	mult_D_table = [
		0x00,
		0x0d,
		0x1a,
		0x17,
		0x34,
		0x39,
		0x2e,
		0x23,
		0x68,
		0x65,
		0x72,
		0x7f,
		0x5c,
		0x51,
		0x46,
		0x4b,
		0xd0,
		0xdd,
		0xca,
		0xc7,
		0xe4,
		0xe9,
		0xfe,
		0xf3,
		0xb8,
		0xb5,
		0xa2,
		0xaf,
		0x8c,
		0x81,
		0x96,
		0x9b,
		0xbb,
		0xb6,
		0xa1,
		0xac,
		0x8f,
		0x82,
		0x95,
		0x98,
		0xd3,
		0xde,
		0xc9,
		0xc4,
		0xe7,
		0xea,
		0xfd,
		0xf0,
		0x6b,
		0x66,
		0x71,
		0x7c,
		0x5f,
		0x52,
		0x45,
		0x48,
		0x03,
		0x0e,
		0x19,
		0x14,
		0x37,
		0x3a,
		0x2d,
		0x20,
		0x6d,
		0x60,
		0x77,
		0x7a,
		0x59,
		0x54,
		0x43,
		0x4e,
		0x05,
		0x08,
		0x1f,
		0x12,
		0x31,
		0x3c,
		0x2b,
		0x26,
		0xbd,
		0xb0,
		0xa7,
		0xaa,
		0x89,
		0x84,
		0x93,
		0x9e,
		0xd5,
		0xd8,
		0xcf,
		0xc2,
		0xe1,
		0xec,
		0xfb,
		0xf6,
		0xd6,
		0xdb,
		0xcc,
		0xc1,
		0xe2,
		0xef,
		0xf8,
		0xf5,
		0xbe,
		0xb3,
		0xa4,
		0xa9,
		0x8a,
		0x87,
		0x90,
		0x9d,
		0x06,
		0x0b,
		0x1c,
		0x11,
		0x32,
		0x3f,
		0x28,
		0x25,
		0x6e,
		0x63,
		0x74,
		0x79,
		0x5a,
		0x57,
		0x40,
		0x4d,
		0xda,
		0xd7,
		0xc0,
		0xcd,
		0xee,
		0xe3,
		0xf4,
		0xf9,
		0xb2,
		0xbf,
		0xa8,
		0xa5,
		0x86,
		0x8b,
		0x9c,
		0x91,
		0x0a,
		0x07,
		0x10,
		0x1d,
		0x3e,
		0x33,
		0x24,
		0x29,
		0x62,
		0x6f,
		0x78,
		0x75,
		0x56,
		0x5b,
		0x4c,
		0x41,
		0x61,
		0x6c,
		0x7b,
		0x76,
		0x55,
		0x58,
		0x4f,
		0x42,
		0x09,
		0x04,
		0x13,
		0x1e,
		0x3d,
		0x30,
		0x27,
		0x2a,
		0xb1,
		0xbc,
		0xab,
		0xa6,
		0x85,
		0x88,
		0x9f,
		0x92,
		0xd9,
		0xd4,
		0xc3,
		0xce,
		0xed,
		0xe0,
		0xf7,
		0xfa,
		0xb7,
		0xba,
		0xad,
		0xa0,
		0x83,
		0x8e,
		0x99,
		0x94,
		0xdf,
		0xd2,
		0xc5,
		0xc8,
		0xeb,
		0xe6,
		0xf1,
		0xfc,
		0x67,
		0x6a,
		0x7d,
		0x70,
		0x53,
		0x5e,
		0x49,
		0x44,
		0x0f,
		0x02,
		0x15,
		0x18,
		0x3b,
		0x36,
		0x21,
		0x2c,
		0x0c,
		0x01,
		0x16,
		0x1b,
		0x38,
		0x35,
		0x22,
		0x2f,
		0x64,
		0x69,
		0x7e,
		0x73,
		0x50,
		0x5d,
		0x4a,
		0x47,
		0xdc,
		0xd1,
		0xc6,
		0xcb,
		0xe8,
		0xe5,
		0xf2,
		0xff,
		0xb4,
		0xb9,
		0xae,
		0xa3,
		0x80,
		0x8d,
		0x9a,
		0x97]
	mult_E_table = [
		0x00,
		0x0e,
		0x1c,
		0x12,
		0x38,
		0x36,
		0x24,
		0x2a,
		0x70,
		0x7e,
		0x6c,
		0x62,
		0x48,
		0x46,
		0x54,
		0x5a,
		0xe0,
		0xee,
		0xfc,
		0xf2,
		0xd8,
		0xd6,
		0xc4,
		0xca,
		0x90,
		0x9e,
		0x8c,
		0x82,
		0xa8,
		0xa6,
		0xb4,
		0xba,
		0xdb,
		0xd5,
		0xc7,
		0xc9,
		0xe3,
		0xed,
		0xff,
		0xf1,
		0xab,
		0xa5,
		0xb7,
		0xb9,
		0x93,
		0x9d,
		0x8f,
		0x81,
		0x3b,
		0x35,
		0x27,
		0x29,
		0x03,
		0x0d,
		0x1f,
		0x11,
		0x4b,
		0x45,
		0x57,
		0x59,
		0x73,
		0x7d,
		0x6f,
		0x61,
		0xad,
		0xa3,
		0xb1,
		0xbf,
		0x95,
		0x9b,
		0x89,
		0x87,
		0xdd,
		0xd3,
		0xc1,
		0xcf,
		0xe5,
		0xeb,
		0xf9,
		0xf7,
		0x4d,
		0x43,
		0x51,
		0x5f,
		0x75,
		0x7b,
		0x69,
		0x67,
		0x3d,
		0x33,
		0x21,
		0x2f,
		0x05,
		0x0b,
		0x19,
		0x17,
		0x76,
		0x78,
		0x6a,
		0x64,
		0x4e,
		0x40,
		0x52,
		0x5c,
		0x06,
		0x08,
		0x1a,
		0x14,
		0x3e,
		0x30,
		0x22,
		0x2c,
		0x96,
		0x98,
		0x8a,
		0x84,
		0xae,
		0xa0,
		0xb2,
		0xbc,
		0xe6,
		0xe8,
		0xfa,
		0xf4,
		0xde,
		0xd0,
		0xc2,
		0xcc,
		0x41,
		0x4f,
		0x5d,
		0x53,
		0x79,
		0x77,
		0x65,
		0x6b,
		0x31,
		0x3f,
		0x2d,
		0x23,
		0x09,
		0x07,
		0x15,
		0x1b,
		0xa1,
		0xaf,
		0xbd,
		0xb3,
		0x99,
		0x97,
		0x85,
		0x8b,
		0xd1,
		0xdf,
		0xcd,
		0xc3,
		0xe9,
		0xe7,
		0xf5,
		0xfb,
		0x9a,
		0x94,
		0x86,
		0x88,
		0xa2,
		0xac,
		0xbe,
		0xb0,
		0xea,
		0xe4,
		0xf6,
		0xf8,
		0xd2,
		0xdc,
		0xce,
		0xc0,
		0x7a,
		0x74,
		0x66,
		0x68,
		0x42,
		0x4c,
		0x5e,
		0x50,
		0x0a,
		0x04,
		0x16,
		0x18,
		0x32,
		0x3c,
		0x2e,
		0x20,
		0xec,
		0xe2,
		0xf0,
		0xfe,
		0xd4,
		0xda,
		0xc8,
		0xc6,
		0x9c,
		0x92,
		0x80,
		0x8e,
		0xa4,
		0xaa,
		0xb8,
		0xb6,
		0x0c,
		0x02,
		0x10,
		0x1e,
		0x34,
		0x3a,
		0x28,
		0x26,
		0x7c,
		0x72,
		0x60,
		0x6e,
		0x44,
		0x4a,
		0x58,
		0x56,
		0x37,
		0x39,
		0x2b,
		0x25,
		0x0f,
		0x01,
		0x13,
		0x1d,
		0x47,
		0x49,
		0x5b,
		0x55,
		0x7f,
		0x71,
		0x63,
		0x6d,
		0xd7,
		0xd9,
		0xcb,
		0xc5,
		0xef,
		0xe1,
		0xf3,
		0xfd,
		0xa7,
		0xa9,
		0xbb,
		0xb5,
		0x9f,
		0x91,
		0x83,
		0x8d]

	mult_table = [None, mult_1_table, mult_2_table, mult_3_table, None, None, None, None,
				  None, mult_9_table, None, mult_B_table, None, mult_D_table, mult_E_table, None]

	mix_mults = [[0x2, 0x3, 0x1, 0x1], [0x1, 0x2, 0x3, 0x1], [0x1, 0x1, 0x2, 0x3], [0x3, 0x1, 0x1, 0x2]]
	unmix_mults = [[0xE, 0xB, 0xD, 0x9], [0x9, 0xE, 0xB, 0xD], [0xD, 0x9, 0xE, 0xB], [0xB, 0xD, 0x9, 0xE]]

	def __init__(self, key):
		self.block_size, self.num_rounds = 0x10, 10  # 128-bit AES
		if len(key) != self.block_size:
			raise ValueError('Key must be of size %X!' % self.block_size)
		self.keys = [list(up('>IIII', key))]
		for i in range(1, self.num_rounds+1):
			new_key = [self.key_schedule_core(self.keys[i-1][3], i) ^ self.keys[i-1][0]]
			for j in range(1, 4):
				new_key.append(self.keys[i-1][j] ^ new_key[j-1])
			self.keys.append(new_key)

	def encrypt(self, data):
		'''Encrypts some data in ECB mode.'''
		out = b''
		while data:
			out += self.encrypt_block_ecb(data[:0x10])
			data = data[0x10:]
		return out

	def decrypt(self, data):
		'''Decrypts some data in EBC mode.'''
		if len(data) % self.block_size:
			raise ValueError('Data is not aligned to block size!')
		out = b''
		while data:
			out += self.decrypt_block_ecb(data[:0x10])
			data = data[0x10:]
		return out

	def encrypt_block_ecb(self, block):
		words = list(up('>IIII', self.pad_block(block)))
		for i in range(len(words)):
			words[i] ^= self.keys[0][i]
		for rnd in range(1, self.num_rounds + 1):
			for i in range(len(words)):
				words[i] = self.send_through_sbox(words[i], self.sbox_enc)
			words = self.shift_columns(words)
			if rnd != self.num_rounds:
				words = self.mix_columns(words)
			for i in range(len(words)):
				words[i] ^= self.keys[rnd][i]
		return pk('>IIII', words[0], words[1], words[2], words[3])

	def decrypt_block_ecb(self, block):
		assert(len(block) == self.block_size)
		words = list(up('>IIII', block))
		for rnd in range(self.num_rounds, 0, -1):
			for i in range(len(words)):
				words[i] ^= self.keys[rnd][i]
			if rnd != self.num_rounds:
				words = self.unmix_columns(words)
			words = self.unshift_columns(words)
			for i in range(len(words)):
				words[i] = self.send_through_sbox(words[i], self.sbox_dec)
		for i in range(len(words)):
			words[i] ^= self.keys[0][i]
		return pk('>IIII', words[0], words[1], words[2], words[3])

	# Helper functions
	def rotate_op(self, word):
		'''Rotate operation'''
		return ((word & 0xFFFFFF) << 8) | ((word & 0xFF000000) >> 24)

	def rcon_op(self, i):
		'''Rcon operation'''
		assert(0 <= i and i < len(self.rcon_table))
		return self.rcon_table[i]

	def send_through_sbox(self, word, sbox=sbox_enc):
		'''Sends a 32-bit word through an sbox.'''
		return (sbox[((word & (0xFF << 0x18)) >> 0x18)] << 0x18) | \
			(sbox[((word & (0xFF << 0x10)) >> 0x10)] << 0x10) | \
			(sbox[((word & (0xFF << 0x08)) >> 0x08)] << 0x08) | \
			(sbox[((word & (0xFF << 0x00)) >> 0x00)] << 0x00)

	def shift_columns(self, words):
		'''Performs column shifting for AES.'''
		new_words = []
		new_words.append((words[0] & 0xFF000000) | (words[1] & 0xFF0000) | (words[2] & 0xFF00) | (words[3] & 0xFF))
		new_words.append((words[1] & 0xFF000000) | (words[2] & 0xFF0000) | (words[3] & 0xFF00) | (words[0] & 0xFF))
		new_words.append((words[2] & 0xFF000000) | (words[3] & 0xFF0000) | (words[0] & 0xFF00) | (words[1] & 0xFF))
		new_words.append((words[3] & 0xFF000000) | (words[0] & 0xFF0000) | (words[1] & 0xFF00) | (words[2] & 0xFF))
		return new_words

	def unshift_columns(self, words):
		'''Performs column unshifting for AES.'''
		new_words = []
		new_words.append((words[0] & 0xFF000000) | (words[3] & 0xFF0000) | (words[2] & 0xFF00) | (words[1] & 0xFF))
		new_words.append((words[1] & 0xFF000000) | (words[0] & 0xFF0000) | (words[3] & 0xFF00) | (words[2] & 0xFF))
		new_words.append((words[2] & 0xFF000000) | (words[1] & 0xFF0000) | (words[0] & 0xFF00) | (words[3] & 0xFF))
		new_words.append((words[3] & 0xFF000000) | (words[2] & 0xFF0000) | (words[1] & 0xFF00) | (words[0] & 0xFF))
		return new_words

	def mix_columns(self, words):
		'''Performs column mixing for 128-bit AES'''
		return [self.mix_column(words[0], self.mix_mults), self.mix_column(words[1], self.mix_mults),
				self.mix_column(words[2], self.mix_mults), self.mix_column(words[3], self.mix_mults)]

	def unmix_columns(self, words):
		'''Performs column unmixing for 128-bit AES'''
		return [self.mix_column(words[0], self.unmix_mults), self.mix_column(words[1], self.unmix_mults),
				self.mix_column(words[2], self.unmix_mults), self.mix_column(words[3], self.unmix_mults)]

	def mix_column(self, word, mults):
		'''Performs column mixing on a single column'''
		return ((self.mix(word, mults[0])) << 0x18) | \
			((self.mix(word, mults[1])) << 0x10) | \
			((self.mix(word, mults[2])) << 0x08) | \
			((self.mix(word, mults[3])) << 0x00)

	def mix(self, word, mix):
		'''Mixes a word according to a given multiplier.'''
		return (self.mult_table[mix[0]][((word >> 0x18) & 0xFF)]) ^ \
			(self.mult_table[mix[1]][((word >> 0x10) & 0xFF)]) ^ \
			(self.mult_table[mix[2]][((word >> 0x08) & 0xFF)]) ^ \
			(self.mult_table[mix[3]][((word >> 0x00) & 0xFF)]) & 0xFF

	def key_schedule_core(self, word, i, sbox=sbox_enc):
		'''Performs core key scheduling operation.'''
		return self.send_through_sbox(self.rotate_op(word), sbox) ^ (self.rcon_op(i) << 0x18)

	def pad_block(self, block):
		'''Pads a block using CMS padding.'''
		assert(len(block) <= self.block_size)
		num_pad = self.block_size - len(block)
		right = (chr(num_pad) * num_pad).encode()
		return block + right
